Method of adjusting amount of liquid crystal in a LCD device including reducing the thickness of a seal member to form a repair region by laser heating a metal pattern thereunder

ABSTRACT

A method for adjusting an amount of liquid crystal in a liquid crystal display (LCD) device includes injecting a liquid crystal into a liquid crystal receiving space. The liquid crystal receiving space is disposed between a first substrate, a second substrate that faces the first substrate, and a sealing member interposed between the first and second substrates. The method for adjusting an amount of liquid crystal in a liquid crystal display (LCD) device further includes reducing a thickness of the sealing member at a predetermined portion of the sealing member to form a repair region, and pressurizing the liquid crystal to break the sealing member at the repair region to discharge some of the liquid crystal from the liquid crystal receiving space, so as to adjust the amount of the liquid crystal in the liquid crystal receiving space. The method for adjusting an amount of liquid crystal in a liquid crystal display (LCD) device also includes resealing the broken repair region of the sealing member.

This application claims priority to Korean Patent Application Nos.57193/2006, filed on Jun. 26, 2006, and 57196/2006, filed on Jun. 26,2006, both of which are incorporated herein by reference.

FIELD

The present invention relates to a method for adjusting the amount ofliquid crystal in a liquid crystal display (LCD) device, and moreparticularly, to a method for adjusting the amount of liquid crystal inan LCD device for precisely controlling excessively injected liquidcrystal.

BACKGROUND

An information processing apparatus that can quickly process a largeamount of data, and a display device that displays data processed by theinformation processing apparatus as an image are under rapiddevelopment.

LCD devices are the most representative display devices. LCD devicesdisplay an image using liquid crystal. Liquid crystal changes itsmolecular arrangement when an electric field is applied (an electricalbehavior) and transmits light at different light transmitting indices(transmittances) depending on its molecular arrangement (an opticalbehavior).

For displaying an image using liquid crystal, an LCD device includes aliquid crystal controlling part that controls the arrangement oralignment of liquid crystal molecules and a light providing part thatprovides light to the liquid crystal controlling part.

The liquid crystal controlling part includes a pair of facing substratesand a liquid crystal layer formed between the substrates. The substratesgenerate an electric field for driving the liquid crystal layer.Generally, the liquid crystal layer has a very thin thickness of aboutseveral micrometers.

The thin liquid crystal layer is formed between the substrates by avacuum injection method, a drop filling method, and so on.

In the vacuum injection method, a vacuum is formed between thesubstrates and then liquid crystal is injected between the substrates.In the drop filling method, liquid crystal is dropped onto one of thesubstrates and then the other substrate is coupled to the substratewhere the liquid crystal is dropped.

However, when the liquid crystal is not sufficiently injected betweenthe substrates, a void can be formed between the substrates. In thiscase, an image is not displayed at the void.

On the other hand, when the liquid crystal is excessively injectedbetween the substrates, the liquid crystal moves down by gravity whenthe LCD device is placed in an upright position. In this case, an imageis not properly displayed at a lower portion of the LCD device.

SUMMARY

According to one embodiment of the present invention, a method foradjusting an amount of liquid crystal in a liquid crystal display (LCD)device includes injecting a liquid crystal into a liquid crystalreceiving space. The liquid crystal receiving space is disposed betweena first substrate, a second substrate that faces the first substrate,and a sealing member interposed between the first and second substrates.The method for adjusting an amount of liquid crystal in a liquid crystaldisplay (LCD) device further includes reducing a thickness of thesealing member at a predetermined portion of the sealing member to forma repair region, and pressurizing the liquid crystal to break thesealing member at the repair region to discharge some of the liquidcrystal from the liquid crystal receiving space, so as to adjust theamount of the liquid crystal in the liquid crystal receiving space. Themethod for adjusting an amount of liquid crystal in a liquid crystaldisplay (LCD) device also includes resealing the broken repair region ofthe sealing member.

In another aspect of the present invention, there is provided a methodfor adjusting the amount of liquid crystal in a liquid crystal display(LCD) device. The method includes injecting a liquid crystal into aliquid crystal receiving space. The liquid crystal receiving space isdisposed between a first substrate, a second substrate that faces thefirst substrate, and a sealing member interposed between the first andsecond substrates. The method further includes disposing a mask on thefirst substrate. The mask includes an opening corresponding to a metalmember that overlaps the sealing member. The method also includesirradiating a light onto the metal member through the opening of themask to narrow a portion of the sealing member to form a repair region,pressurizing the liquid crystal to discharge some of the liquid crystalfrom the liquid crystal receiving space through the repair region of thesealing member, and resealing the repair region of the sealing member.

According to another embodiment of the present invention, an LCD panelcomprises a first substrate, a second substrate that faces the firstsubstrate, with a liquid crystal disposed between the first and secondsubstrates, and a sealing member interposed between the first and secondsubstrates. The LCD panel further comprises a liquid crystal receivingspace. The liquid crystal receiving space is disposed between the firstsubstrate, the second substrate that faces the first substrate, and thesealing member interposed between the first and second substrates. TheLCD panel also comprises a mask on the first substrate. The maskincludes an opening corresponding to a metal member that overlaps thesealing member. The LCD panel further includes a repair region. Therepair region is a portion of the sealing member that is narrowed by alight irradiated onto the metal member through the opening of the mask.Some of the liquid crystal from the liquid crystal receiving space isdischarged through the repair region of the sealing member.

According to yet another embodiment of the present invention, an LCDapparatus comprises an LCD panel and a case that supports the LCD panel.The LCD panel comprises a first substrate, a second substrate that facesthe first substrate, with a liquid crystal disposed between the firstand second substrates, and a sealing member interposed between the firstand second substrates. The LCD panel further comprises a liquid crystalreceiving space. The liquid crystal receiving space is disposed betweenthe first substrate, the second substrate that faces the firstsubstrate, and the sealing member interposed between the first andsecond substrates. The LCD panel also comprises a mask on the firstsubstrate. The mask includes an opening corresponding to a metal memberthat overlaps the sealing member. The LCD panel further includes arepair region. The repair region is a portion of the sealing member thatis narrowed by a light irradiated onto the metal member through theopening of the mask. Some of the liquid crystal from the liquid crystalreceiving space is discharged through the repair region of the sealingmember.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 is a flowchart for explaining a method for adjusting the amountof liquid crystal in an LCD device according to a first embodiment ofthe present invention;

FIG. 2 is a cross sectional view illustrating an LCD device to which themethod of FIG. 1 is applied;

FIG. 3 is a partial sectional view illustrating an arrangement of ametal pattern and a sealing member in the LCD device of FIG. 2;

FIG. 4 is a view illustrating removing of an overlapped region betweenthe sealing member and the metal pattern depicted in FIG. 3 by using alaser beam;

FIG. 5 is a plan view illustrating a repair region of the sealingmember;

FIG. 6 is a sectional view illustrating resealing of a broken repairregion of the sealing member depicted in FIG. 5;

FIG. 7 is a plan view illustrating a mask and a sealing member accordingto a second embodiment of the present invention;

FIG. 8 is a perspective view illustrating the mask and the sealingmember depicted in FIG. 7;

FIG. 9 is a sectional view illustrating a process of forming a repairregion using the mask;

FIG. 10 is a plan view illustrating the repair region formed at thesealing member; and

FIG. 11 is a sectional view illustrating resealing of the repair region.

DETAILED DESCRIPTION

A method for adjusting the amount of liquid crystal in an LCD devicewill now be described more fully with reference to the accompanyingdrawings, in which exemplary embodiments of the invention are shown. Theinvention may, however, be embodied in many different forms and shouldnot be construed as being limited to the embodiments set forth herein;rather, these embodiments are provided so that this disclosure will bethorough and complete, and will fully convey the concept of theinvention to those skilled in the art. In the drawings, dimensions of afirst substrate, a second substrate, a sealing member, liquid crystal, arepair region, a mask, and other elements and structures are exaggeratedfor clarity. It will also be understood that when an element orstructure, such as a first substrate, a second substrate, a sealingmember, liquid crystal, a repair region, or a mask, is referred to asbeing “on”, “above”, or “under” another element or structure, it can bedirectly on, above or under another element or structure, or interveningelements or structures may also be present. Further, it will beunderstood that although the terms first and second are used herein todescribe various elements or structures (e.g., a first substrate or asecond substrate), these elements or structures should not be limited bythese terms. These terms are only used to distinguish one element orstructure from another element or structure. Therefore, the terms firstand second can be used selectively or interchangeably for elements orstructures such as substrates. For example, a first substrate could betermed as a second substrate, and similarly, a second substrate could betermed as a first substrate.

FIG. 1 is a flowchart for explaining a method for adjusting the amountof liquid crystal in an LCD device according to a first embodiment ofthe present invention, and FIG. 2 is a cross sectional view illustratingan LCD device to which the method of FIG. 1 is applied.

Referring to FIGS. 1 and 2, in operation S10, liquid crystal is injectedinto an LCD device 100 to form a liquid crystal layer 10. Liquid crystalcan be injected by a vacuum injection method or a drop filling method.

The LCD device 100 will now be described in detail with reference toFIG. 2.

The LCD device 100 includes a first substrate 20, a second substrate 30,the liquid crystal layer 10, a sealing member 40, and a metal pattern50.

The first substrate 20 includes a first transparent substrate 21 such asa glass substrate, thin film transistors 22, and pixel electrodes PE.

The thin film transistors 22 are formed on the first transparentsubstrate 21. According to one embodiment of the present invention, aplurality of thin film transistors is formed on the first transparentsubstrate 21 in accordance with the resolution of the LCD device 100.For example, when the resolution of the LCD device 100 is 1024×768,1024×768×3 thin film transistors 22 may be formed on the firsttransparent substrate 21 in a matrix format.

Each of the thin film transistors 22 includes a gate electrode Gconnected to a gate line (not shown), a gate insulation layer GIinsulating the gate electrode G, a channel pattern C formed on the gateinsulation layer GI above the gate electrode G, a source electrode S anda drain electrode D that are formed on the channel pattern C. Thechannel pattern C may include an n+ amorphous silicon pattern (notshown) formed by ion-doping an amorphous silicon pattern with aconductive impurity to a high concentration.

The source electrode S is connected to a data line (not shown) formedperpendicular to the gate line. The source electrode S and the drainelectrode D are formed on the channel pattern C at a predetermineddistance from each other.

The pixel electrode PE is electrically connected to the drain electrodeD of the thin film transistor 22. According to one embodiment of thepresent invention, the pixel electrode PE includes a transparentconductive material. The pixel electrode PE may be formed of a materialsuch as an indium tin oxide (ITO), an indium zinc oxide (IZO), or anamorphous indium tin oxide (a-ITO).

The second substrate 30 includes a second transparent substrate 31 suchas a glass substrate, a black matrix 32, and a color filter 34.

The black matrix 32 is formed under the second transparent substrate 31.The black matrix 32 may be formed of a material having a high lightabsorbance such as chrome and a chrome oxide. When viewed from the topin FIG. 2, the black matrix 32 is formed between the pixel electrodes PEformed on the first substrate 20.

Since the pixel electrodes PE of the first substrate 20 are arranged ina matrix format, the black matrix 32 can have a grid shape. The blackmatrix 32 screens the thin film transistors 22 arranged on the firstsubstrate 20. Further, the back matrix 32 absorbs light incident fromthe outside, thereby improving the contrast of a displaying image.

The color filter 34 is formed in each opening defined in the blackmatrix 32. The color filter 34 formed in each opening of the blackmatrix 32 includes a red (R) color filter transmitting a red lightcomponent of white light, a green (G) color filter transmitting a greenlight component of white light, and a blue (B) color filter transmittinga blue light component of white light.

The sealing member 40 is disposed between the facing first and secondsubstrates 20 and 30. For example, the sealing member 40 can be formedbetween edges of the first and second substrates 20 and 30 to provide aliquid crystal receiving space between the first and second substrates20 and 30. According to one embodiment of the present invention, thesealing member 40 may include a photocurable material that is hardenedby light such as ultraviolet rays.

The liquid crystal layer 10 is filled in the liquid crystal receivingspace formed by the sealing member 40. The liquid crystal layer 10 mayinclude twist nematic liquid crystal, vertical alignment liquid crystal,or the like.

FIG. 3 is a partial sectional view illustrating an arrangement of themetal pattern 50 and the sealing member 40.

Referring to FIG. 3, the metal pattern 50 may be formed on the firstsubstrate 20. In detail, the metal pattern 50 is formed between thesealing member 40 and the first substrate 20. The metal pattern 50 has apiece shape. The metal pattern 50 and the sealing member 40 are formedoverlapping each other.

The metal pattern 50 is formed at an outer side 42 of the sealing member40 opposite to an inner side 44 of the sealing member 40 contacting theliquid crystal layer 10. When the thickness of the sealing member 40 isT, the overlapping region between the metal pattern 50 and the sealingmember 40 occupies about 85% to 95% of the thickness (T).

Therefore, the non-overlapping region of the sealing member 40 with themetal pattern 50 has a thickness (t) ranging from 5% to 15% of the totalthickness T of the sealing member 40. Hereinafter, the overlappingregion of the metal pattern 50 with the sealing member 40 will bedenoted by reference numeral 56, and the remaining non-overlappingregion (exposed region) will be denoted by reference numeral 55.

According to one embodiment of the present invention, the metal pattern50 may be formed of the same material as the gate electrode G, thesource/drain electrodes S and D, or the pixel electrode PE of the thinfilm transistor 22. That is, the metal pattern 50 can be formed ofaluminum, an aluminum alloy, ITO, IZO, or a-ITO.

Referring again to FIGS. 1 and 2, after the liquid crystal layer 10 isformed in the LCD device 100, it is determined whether liquid crystalwas excessively injected into the LCD device 100. If so, the excessiveamount of the injected liquid crystal is removed from the LCD device100.

FIG. 4 is a view illustrating removing of the overlapped region betweenthe sealing member 40 and the metal pattern 50 using a laser beam, andFIG. 5 is a plan view illustrating a remaining region of the sealingmember 40.

Referring to FIGS. 1, 4, and 5, in order to adjust the amount of liquidcrystal of the liquid crystal layer 10 by discharging the excessiveamount of the liquid crystal from the liquid crystal layer 10, a repairregion 45 is formed at the sealing member 40 in operation S20.

Referring to FIG. 4, a laser beam generating device 60 emits a laserbeam 65 onto the overlapping region 56 (referred to in FIG. 3) of themetal pattern 50 to form the repair region 45.

According to one embodiment of the present invention, the laser beam 65is irradiated onto the overlapping region 56 of the metal patternthrough the second substrate 30 and the sealing member 40. The laserbeam 65 is not absorbed by the second substrate 30 and the sealingmember 40 but absorbed mainly by the metal pattern.

To this end, the laser beam 65 has a wavelength in the range of 800 nmto 1,200 nm. When the wavelength of the laser beam 65 is greater than1,200 nm, the second substrate 30 and the sealing member 40 can bedamaged by the light 65. On the other hand, the wavelength of the laserbeam 65 is lower than 800 nm, it is difficult to provide sufficientenergy to the metal pattern 50 because of a low energy level of thelaser beam 65.

Therefore, it is preferable that the wavelength of the laser beam 65 bein the range of 800 nm to 1,200 nm.

When receiving the laser beam 65, the metal pattern 50 is rapidly burnt.Accordingly, a portion of the sealing member 40 corresponding to theoverlapping region 56 of the metal pattern 50 is removed together withthe metal pattern 50, thereby forming the repair region 45 and aremaining region 45 a as shown in FIGS. 4 and 5. The repair region 45and the remaining region 45 a can be formed at the sealing member 40 attwo or more places.

According to one embodiment of the present invention, the repair region45 of the sealing member 40 corresponds to the overlapping region 56 ofthe metal pattern 50. Since the overlapping region 56 occupies about 85%to 95% of the thickness (T) of the sealing member 40, the sealing member40 has a thin thickness at the repair region 45. That is, the thicknessof the remaining region 45 a ranges from 5% to 15% of the thickness (T)of the sealing member.

Referring again to FIG. 1, after the repair region 45 is formed at thesealing member 40, the excessive amount of liquid crystal injected intothe liquid crystal layer 10 of the LCD device 100 is adjusted throughthe repair region 45 in operation S30.

For this adjustment, a pressure is applied to the LCD display 100, andthe applied pressure is transmitted to the liquid crystal layer 10.Then, the pressure is transmitted to the remaining region 45 a of thesealing member 40. If the pressure acting on the remaining region 45 ais larger than the strength of the remaining region 45 a, the remainingregion 45 a is broken.

Then, excessively injected liquid crystal is discharged from the LCDdevice 100 through the broken remaining region 45 a, so that the amountof liquid crystal of the liquid crystal layer 10 can be properlyadjusted.

FIG. 6 is a sectional view illustrating resealing of the brokenremaining region 45 a.

Referring to FIG. 6, to prevent outside air from flowing into the liquidcrystal layer 10 through the broken remaining region 45 a, aphotocurable material 70 is applied to the broken remaining region 45 aand then light is irradiated to the photocurable material 70 forresealing the broken sealing member 40 in operation S40. Preferably, thephotocurable material 70 may be a UV-curable material hardening byultraviolet rays.

FIG. 7 is a plan view illustrating a mask and a sealing member accordingto a second embodiment of the present invention, and FIG. 8 is aperspective view illustrating the mask and the sealing member depictedin FIG. 7. FIG. 9 is a sectional view for illustrating a process forforming a repair region using the mask. FIG. 10 is a plan viewillustrating the repair region formed at the sealing member. FIG. 11 isa sectional view illustrating resealing of the repair region.

In the second embodiment of the present invention, the liquid crystaldisplay panel, the sealing member, and the metal pattern (member) havesubstantially the identical structures as in the first embodimentillustrated in FIGS. 1 to 3. Thus, descriptions thereof will be omitted.Further, like reference numerals denote like elements.

Referring to FIGS. 7 and 8, a mask 80 includes a first surface 82 and asecond surface 84. Preferably, the mask 80 is formed of a material thatis not damaged by a laser beam.

The first surface 82 may be flatly formed along a top surface of thesecond substrate 30 of the LCD device 100, and the second surface 84 mayextend downwardly from an edge of the first surface 82 along a sidesurface of the second substrate 30. According to one embodiment of thepresent invention, the first surface 82 and the second surface 84 forman L-shape. The second surface 84 facilitates alignment between anopening 81 (described later) and the overlapping region 56 of the metalmember 50 formed under the sealing member 40.

The opening 81 is formed in the first surface 82. The opening 81 may berectangular. Particularly, the opening 81 is properly sized foralignment with the overlapping region 56 of the metal member 50. Theouter side 42 of the sealing member 40, which is opposite to the innerside 44 of the sealing member 40 contacting the liquid crystal layer 10,is exposed by the opening 81. Reference numeral 45 denotes a repairregion formed at the sealing member 40.

Referring to FIG. 9, to form the repair region 45, a laser beam 65generated from the laser beam generating unit 60 is irradiated throughthe opening 81 formed in the first surface 82 of the mask 80.

Next, the laser beam 65 reaches the overlapping region 56 of the metalmember 50 after sequentially passing through the opening 81, the secondsubstrate 30, and the sealing member 40.

Even when the laser beam 65 departs from its optical path due tovibrations or impacts applied to the laser beam generating unit 60and/or the LCD device 100, the mask 80 having the opening 81 preventsthe laser beam 65 from reaching an undesired portion of the sealingmember 40.

According to one embodiment of the present invention, the laser beam 65is not substantially absorbed by the second substrate 30 and the sealingmember 40. However, the metal member 50 absorbs most of the laser beam65, and thus the metal member 50 is rapidly heated.

To effectively form the repair region 45 at the sealing member 40, it ispreferable that the laser beam 65 have a wavelength in the range of 800nm to 1200 nm. When the wavelength of the laser beam 65 is greater than1200 nm, the second substrate 30, the sealing member 40, and the firstsubstrate 20 can be damaged by the laser beam 65. On the other hand,when the wavelength of the laser beam 65 is lower than 800 nm, it isdifficult to burn down the metal member 50 because of a low energy levelof the laser beam 65.

Therefore, when the laser beam 65 has a wavelength in the range of about800 nm to 1200 nm and is irradiated onto the overlapping region 56 ofthe metal member 50 through the opening 81, the metal member 50 can beeasily burnt by absorbing the energy of the laser beam 65.

When the metal member 50 is burnt down, a portion of the sealing member40 corresponding to the metal member 50 is also removed, thereby formingthe repair region 45 and the remaining region 45 a at the sealing member40 as shown in FIG. 10. The repair region 45 can be formed on thesealing member 40 at two or more places.

The repair region 45 is defined as a region corresponding to theoverlapping region 56 of the metal member 50. Since the overlappingregion 56 of the metal member 50 occupies about 85% to 95% of thethickness (T) of the sealing member 40, the sealing member 40 has a thinthickness at the repair region 45. That is, the thickness of theremaining region 45 a ranges from 5% to 15% of the thickness (T) of thesealing member.

As explained above, the overlapping region 56 of the metal member 50 isremoved using the laser beam 65. As a result, the remaining region 45 ais formed at the seaming member 40. Even when the laser beam 65 isdeviated from its original optical path, the remaining region 45 a canbe clearly formed along an intended contour line owing to the opening 81formed in the mask 80.

After the repair region 45 is formed at the sealing member 40,excessively injected liquid crystal is released from the LCD device 100using the repair region 45.

To this end, a pressure is applied to the LCD device 100, and thispressure is transmitted to the liquid crystal layer 10. Then thepressure is transmitted to the sealing member 40.

When the pressure applied to the sealing member 40 is sufficiently high,the remaining region 45 a of the sealing member 40 is broken at therepair region 45.

Then, some of the liquid crystal injected into the LCD device 100 isdischarged through the broken remaining region 45 a of the sealingmember 40. Therefore, the amount of liquid crystal filled in the LCDdevice 100 can be properly adjusted.

Referring to FIG. 11, outside air can be introduced into the LCD device100 through the broken remaining region 45 a.

To prevent the inflow of the outside air to the LCD device 100, aphotocurable material 70 is applied to the broken remaining region 45 aof the sealing member 40, and light is irradiated to the appliedphotocurable material 70. In this way, the broken remaining region 45 aof the sealing member can be resealed. It is preferable that thephotocurable material 70 is an UV-curable material hardening by UV rays.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present invention. Thus,it is intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A method for adjusting an amount of liquid crystal in an LCD (liquidcrystal display) device, the method comprising: injecting a liquidcrystal into a liquid crystal panel having a sealing member for forminga liquid crystal receiving space; reducing a thickness of the sealingmember at a predetermined portion of the sealing member to form a repairregion; pressurizing the liquid crystal to break the sealing member atthe repair region to discharge some of the liquid crystal from theliquid crystal receiving space, so as to adjust the amount of the liquidcrystal in the liquid crystal receiving space; and resealing the brokenrepair region of the sealing member, wherein the reducing the thicknesscomprises: heating a metal pattern that overlaps the sealing memberunder the sealing member; and burning a portion of the sealing memberthat overlaps the metal pattern by the heated metal pattern, wherein theheating the metal pattern is performed using a laser beam.
 2. The methodaccording to claim 1, wherein the laser beam has a wavelength rangingfrom about 800 nm to 1200 nm.
 3. The method according to claim 1,wherein the metal pattern is formed of at least one material selectedfrom the group consisting of an aluminum, an aluminum alloy, ITO (indiumtin oxide), and IZO (indium zinc oxide).
 4. The method according toclaim 1, further comprising forming one or more additional repairregions at the sealing member.
 5. The method according to claim 1,wherein the thickness of the predetermined portion of the sealing memberis about 5% to 15% of that of the sealing member.
 6. The methodaccording to claim 1, wherein the resealing of the broken repair regioncomprises: applying a photocurable material to the broken repair regionof the sealing member; and irradiating a light to the photocurablematerial.